Abstract
1. Optical fibres were used to excite and record fluorescence from the lumenal face of rat aorta or tail artery loaded with fura-2. 2. Acetylcholine (ACh) evoked an endothelium-dependent rise in the fura-2 340/380 nm excitation ratio in both vessels. High [K+] or phenylephrine evoked an endothelium-independent rise in ratio in tail artery but failed to increase the ratio in aorta. These observations indicate that fura-2 fluorescence and therefore cytosolic calcium concentration ([Ca2+]i) may be selectively recorded from the endothelium of intact rat aorta. 3. In aortic endothelium, resting [Ca2+]i was 95 +/- 8 nM (n = 44). ACh evoked a monophasic rise in [Ca2+]i which was temporally coincident with a membrane hyperpolarization. 4. ATP in most (22/35) preparations evoked a rise in [Ca2+]i which declined towards resting and was followed by a secondary rise. The biphasic [Ca2+]i responses were accompanied by biphasic electrical responses of initial hyperpolarization followed by depolarization above the resting potential and subsequent restoration towards rest. In the presence of high [K+] or the K+ ionophore valinomycin, ATP did not evoke changes in membrane potential and only monophasic rises in [Ca2+]i were observed. In some (7/35) preparations, ATP evoked oscillations in [Ca2+]i, with membrane potential oscillating in antiphase. 5. These data suggest interplay between [Ca2+]i and membrane potential in the generation of agonist-evoked responses in native endothelium in situ. The observed oscillations in [Ca2+]i imply spatio-temporal synchronization of Ca2+ signalling in large groups of endothelial cells in intact rat aorta.
Full text
PDF![309](https://cdn.ncbi.nlm.nih.gov/pmc/blobs/b769/1156759/876dca721be1/jphysiol00305-0015.png)
![310](https://cdn.ncbi.nlm.nih.gov/pmc/blobs/b769/1156759/d1735a628e99/jphysiol00305-0016.png)
![311](https://cdn.ncbi.nlm.nih.gov/pmc/blobs/b769/1156759/24d0a28d475f/jphysiol00305-0017.png)
![312](https://cdn.ncbi.nlm.nih.gov/pmc/blobs/b769/1156759/5cc52dcef418/jphysiol00305-0018.png)
![313](https://cdn.ncbi.nlm.nih.gov/pmc/blobs/b769/1156759/06c06779f870/jphysiol00305-0019.png)
![314](https://cdn.ncbi.nlm.nih.gov/pmc/blobs/b769/1156759/a8ae332e8662/jphysiol00305-0020.png)
![315](https://cdn.ncbi.nlm.nih.gov/pmc/blobs/b769/1156759/602e85915be0/jphysiol00305-0021.png)
![316](https://cdn.ncbi.nlm.nih.gov/pmc/blobs/b769/1156759/ec861ffabaa8/jphysiol00305-0022.png)
![317](https://cdn.ncbi.nlm.nih.gov/pmc/blobs/b769/1156759/ef1292e819c6/jphysiol00305-0023.png)
Images in this article
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Batlle D. C., Godinich M., LaPointe M. S., Munoz E., Carone F., Mehring N. Extracellular Na+ dependency of free cytosolic Ca2+ regulation in aortic vascular smooth muscle cells. Am J Physiol. 1991 Nov;261(5 Pt 1):C845–C856. doi: 10.1152/ajpcell.1991.261.5.C845. [DOI] [PubMed] [Google Scholar]
- Busse R., Fichtner H., Lückhoff A., Kohlhardt M. Hyperpolarization and increased free calcium in acetylcholine-stimulated endothelial cells. Am J Physiol. 1988 Oct;255(4 Pt 2):H965–H969. doi: 10.1152/ajpheart.1988.255.4.H965. [DOI] [PubMed] [Google Scholar]
- Carter T. D., Ogden D. Acetylcholine-stimulated changes of membrane potential and intracellular Ca2+ concentration recorded in endothelial cells in situ in the isolated rat aorta. Pflugers Arch. 1994 Oct;428(5-6):476–484. doi: 10.1007/BF00374568. [DOI] [PubMed] [Google Scholar]
- Falcone J. C., Kuo L., Meininger G. A. Endothelial cell calcium increases during flow-induced dilation in isolated arterioles. Am J Physiol. 1993 Feb;264(2 Pt 2):H653–H659. doi: 10.1152/ajpheart.1993.264.2.H653. [DOI] [PubMed] [Google Scholar]
- Gosink E. C., Forsberg E. J. Effects of ATP and bradykinin on endothelial cell Ca2+ homeostasis and formation of cGMP and prostacyclin. Am J Physiol. 1993 Dec;265(6 Pt 1):C1620–C1629. doi: 10.1152/ajpcell.1993.265.6.C1620. [DOI] [PubMed] [Google Scholar]
- Grynkiewicz G., Poenie M., Tsien R. Y. A new generation of Ca2+ indicators with greatly improved fluorescence properties. J Biol Chem. 1985 Mar 25;260(6):3440–3450. [PubMed] [Google Scholar]
- Hallam T. J., Pearson J. D., Needham L. A. Thrombin-stimulated elevation of human endothelial-cell cytoplasmic free calcium concentration causes prostacyclin production. Biochem J. 1988 Apr 1;251(1):243–249. doi: 10.1042/bj2510243. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Laskey R. E., Adams D. J., Cannell M., van Breemen C. Calcium entry-dependent oscillations of cytoplasmic calcium concentration in cultured endothelial cell monolayers. Proc Natl Acad Sci U S A. 1992 Mar 1;89(5):1690–1694. doi: 10.1073/pnas.89.5.1690. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Laskey R. E., Adams D. J., van Breemen C. Cytosolic [Ca2+] measurements in endothelium of rabbit cardiac valves using imaging fluorescence microscopy. Am J Physiol. 1994 May;266(5 Pt 2):H2130–H2135. doi: 10.1152/ajpheart.1994.266.5.H2130. [DOI] [PubMed] [Google Scholar]
- Marchenko S. M., Sage S. O. Electrical properties of resting and acetylcholine-stimulated endothelium in intact rat aorta. J Physiol. 1993 Mar;462:735–751. doi: 10.1113/jphysiol.1993.sp019579. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Marchenko S. M., Sage S. O. Mechanism of acetylcholine action on membrane potential of endothelium of intact rat aorta. Am J Physiol. 1994 Jun;266(6 Pt 2):H2388–H2395. doi: 10.1152/ajpheart.1994.266.6.H2388. [DOI] [PubMed] [Google Scholar]
- McDonald T. F., Pelzer S., Trautwein W., Pelzer D. J. Regulation and modulation of calcium channels in cardiac, skeletal, and smooth muscle cells. Physiol Rev. 1994 Apr;74(2):365–507. doi: 10.1152/physrev.1994.74.2.365. [DOI] [PubMed] [Google Scholar]
- Moncada S., Palmer R. M., Higgs E. A. Nitric oxide: physiology, pathophysiology, and pharmacology. Pharmacol Rev. 1991 Jun;43(2):109–142. [PubMed] [Google Scholar]
- Rotrosen D., Gallin J. I. Histamine type I receptor occupancy increases endothelial cytosolic calcium, reduces F-actin, and promotes albumin diffusion across cultured endothelial monolayers. J Cell Biol. 1986 Dec;103(6 Pt 1):2379–2387. doi: 10.1083/jcb.103.6.2379. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Sage S. O., Adams D. J., van Breemen C. Synchronized oscillations in cytoplasmic free calcium concentration in confluent bradykinin-stimulated bovine pulmonary artery endothelial cell monolayers. J Biol Chem. 1989 Jan 5;264(1):6–9. [PubMed] [Google Scholar]
- Sage S. O., Merritt J. E., Hallam T. J., Rink T. J. Receptor-mediated calcium entry in fura-2-loaded human platelets stimulated with ADP and thrombin. Dual-wavelengths studies with Mn2+. Biochem J. 1989 Mar 15;258(3):923–926. doi: 10.1042/bj2580923. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Thastrup O., Cullen P. J., Drøbak B. K., Hanley M. R., Dawson A. P. Thapsigargin, a tumor promoter, discharges intracellular Ca2+ stores by specific inhibition of the endoplasmic reticulum Ca2(+)-ATPase. Proc Natl Acad Sci U S A. 1990 Apr;87(7):2466–2470. doi: 10.1073/pnas.87.7.2466. [DOI] [PMC free article] [PubMed] [Google Scholar]